Commercial uses for HCFO-1233zd (1233zd) include foam blowing agent and solvent applications. In such applications, tight control of moisture content is typically needed to meet customer requirements. Occasionally, due to process issues, the moisture level in 1233zd may exceed specification limits.
Various 1233zd production processes have been disclosed. One example is shown in U.S. Pat. No. 8,921,621, which disclosed a process for the production of HCFO-1233zd comprising the steps of: (a) reacting HCC-240 and HF in a high pressure liquid phase reactor, with subsequent steps including step (h) of “feeding the overhead crude HCFO-1233zd stream to a caustic scrubber to remove any remaining acidity and drying the scrubbed stream with a drying agent . . . ”.
In the '621 process, one objective is to provide enough drying agent to remove the water in the process stream, and one must be prepared that the overhead crude HCFO-1233zd vapor stream could be fully saturated with water. In such a case, it is estimated that for every 1,000 pounds of HCFO-1233zd vapor produced, one could need to remove at least 4 pounds of water. Accordingly, if using a typical molecular sieve desiccant, which can adsorb up to about 15 wt % moisture, one would need to use up to about 27 pounds of molecular sieve for every 1,000 pounds of HCFO-1233zd generated in the process. This invention is designed to significantly reduce the desiccant consumption required for such a process.